Update 9-9-18 – I still have a few Lumen tubes left, You can PM me for details on how to order.

Ok, I have had several people ask me if I can make them a lumen Tube / Sphere like mine in recent times. My first sphere was simply too much work (literally months to get it calibrated) to make this possible.

So I decided I needed to make a replacement while this one still worked as a standard to calibrate the new one from. I had also been thinking of improvements for some time and finally got my hands on the right materials and tools to make this possible.

The only real change is in the diffuser. Instead of foam this time I am using some laser cut diffusing sheets that fit perfectly inside the PVC pipe. This makes it much more consistent and repeatable. Interestingly the direction you insert the sheets has a noticeable effect on the readings.

I also put another sheet between the 2nd PVC connection to further spread out the beam to remove any bias for throwers or other lights that these type of spheres can have issues with. The end result is a perfectly smooth wall of light hitting the meter. I fine tune the readings with magic

The best part of all about this sphere is that unlike every other sphere I have ever seen, the lumens will be displayed directly on the meter!

You will not have to run the lux meter readings through one or more calculations just to see what the lumen reading is, you simply stick the light in there and read the lumen directly on the meter. When I am taking dozens or even hundreds of readings a day this is a lifesaver.

In this picture the light is putting out 193 lumens, this same light and mode reads around 195-196 on my old sphere for reference. I can get that closer but have just not had the time with all the mt09R mods and frankly don’t care since I only give it a ~10% accuracy rating anyways.

So I am planning on making a 1 time batch of these spheres. They will all be calibrated by me with my sphere so the readings will be comparable.

These spheres will come with everything in the pictures
The PVC tube itself, able to fit up to ~89mm reflector lights
HS1010A Lux meter like mine
a range of centering rings for different size lights
calibrated to match my sphere within ~5-10% or so (to give some wiggle room since it is impossible to get things perfect)

I have tested this sphere with lights up to 25,000 lumens and it should in theory be able to read well over 100,000 lumens if the light would fit in the tube, although you would have to worry about melting something at that power level.

Ask anyone that has tried to calibrate a sphere from scratch, it is way harder then it sounds. My sphere took me 6+ months and countless lumen readings before I was happy with the readings.

The lumen tube is far from my idea, The credit for the basic lumen tube setup belongs with BLF members from long before my time.

Making it an “integrating lumen tube” by adding the diffusing sheets and the centering rings to make the readings more consistent light to light was simply my evolution of the idea.

The addition of diffusing disks inside the tube also vastly improve the consistency from light to light and removes the advantage that throwers have classically had in PVC light meters.

For a 6” version the cost is extreme, which is why I did not even consider it before. It would be ~$300 + shipping, which would not be cheap at all, it would be a massive box and take up a ton of space and weigh a lot as well. Although the option is on the table if someone is interested.

I really like the 3.5” version myself, it fits most lights and does not take up a ton of space.

So I will assume everyone on the list wants the normal 3.5” version unless you tell me otherwise.

Maybe it’s not really important, but it might be nice in the interest of full disclosure to say in the OP that the “integrating pipe” is not your original idea. Others have been doing it for years. Although, I’ve not seen it done with diffuser material like you have. Thanks for offering this to the community!

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Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
-Ayn Rand

Sadly no, even 4” PVC is not big enough for the GT and getting larger is very very expensive and somewhat hard to find locally. I considered stepping up to that size myself but it was just not worth 4x+ the price.

This can support up to a 3.5” (~89mm) light, which I find covers the vast majority of lights I want to measure. Thus far the GT is basically the only light I have had that would not fit, the TN42 would be just over as well but I don’t have one.

If someone wants a custom larger sphere setup with larger PVC I can do this, it will just cost much more.

Maybe it’s not really important, but it might be nice in the interest of full disclosure to say in the OP that the “integrating pipe” is not your original idea. Others have been doing it for years. Although, I’ve not seen it done with diffuser material like you have. Thanks for offering this to the community!

Yes, the lumen tube is far from my idea, I never intended for it to sound like it was.

Making it an “integrating lumen tube” by adding the diffusing sheets and the centering rings to make the readings more consistent light to light was simply my evolution of the idea.

Out of curiosity for me and maybe others. How much would the lumen tube cost us for the bigger version to accommodate the blf gt? I don’t think this will be the last time companies will be making heads this large. I already have a few lights from acebeam and thrunite that are 4 inch. I believe olight and manker will also release some large head lights.

Out of curiosity for me and maybe others. How much would the lumen tube cost us for the bigger version to accommodate the blf gt? I don’t think this will be the last time companies will be making heads this large. I already have a few lights from acebeam and thrunite that are 4 inch. I believe olight and manker will also release some large head lights.

Hmm, that is a good question. I know the PVC itself was several times the price. If there is interest I will go to a specialty plumbing supply store and see how much it would cost.

Remind me to check into this if I forget, this week is going to be VERY busy for me.

It should be, you only need the very tip of the light sticking through the centering ring for it to work. In fact sticking the light in even 1/2” too far can have a pretty noticeable effect on the readings.

It should be, you only need the very tip of the light sticking through the centering ring for it to work. In fact sticking the light in even 1/2” too far can have a pretty noticeable effect on the readings.

I am thinking of designs like the Armytek Wizard where the cooling fins protrude in front of the bezel, preventing it from lying flat on a diffuser.

Out of curiosity for me and maybe others. How much would the lumen tube cost us for the bigger version to accommodate the blf gt? I don’t think this will be the last time companies will be making heads this large. I already have a few lights from acebeam and thrunite that are 4 inch. I believe olight and manker will also release some large head lights.

Yea I also want to know because I’m interested in the upcoming Astrolux MF03, MF04, MF05, TN42VN, and Acebeam X70 or whatever other high power lights might be coming out.

It should be, you only need the very tip of the light sticking through the centering ring for it to work. In fact sticking the light in even 1/2” too far can have a pretty noticeable effect on the readings.

I am thinking of designs like the Armytek Wizard where the cooling fins protrude in front of the bezel, preventing it from lying flat on a diffuser.

It will not seal perfectly but it should still give a reasonably close reading. You will just need to add a little bit for the light that escapes due to an imperfect seal. After some experience with the tube you will figure out a reasonable amount to add by playing with other lights of similar output and pulling them out of the tube slightly.

Out of curiosity for me and maybe others. How much would the lumen tube cost us for the bigger version to accommodate the blf gt? I don’t think this will be the last time companies will be making heads this large. I already have a few lights from acebeam and thrunite that are 4 inch. I believe olight and manker will also release some large head lights.

Yea I also want to know because I’m interested in the upcoming Astrolux MF03, MF04, MF05, TN42VN, and Acebeam X70 or whatever other high power lights might be coming out.

Ok, I will look into it. I don’t think I will get time to do this until Friday at the earliest, Remind me tomorrow if you can. I will be silly busy the next few days.

It will not seal perfectly but it should still give a reasonably close reading. You will just need to add a little bit for the light that escapes due to an imperfect seal. After some experience with the tube you will figure out a reasonable amount to add by playing with other lights of similar output and pulling them out of the tube slightly.

How about a spare diffuser ring with a custom cutout for the fins so it lies flat? I’m mostly curious because I do a ton of testing with modded Armytek headlamps so it’s worth the extra effort to me.